Novel Process Integration of Methane or Higher Hydrocarbon Pyrolysis Step to Produce Ethylene and Methanol and/or Hydrogen

Abstract

A method for producing ethylene and methanol comprising contacting fuel gas and oxidant gas to produce combustion product; contacting hydrocarbons and combustion product to produce pyrolysis product comprising unconverted hydrocarbons, acetylene, ethylene, CO, H2, H2O, CO2; separating pyrolysis product into CO2 stream and CO2 free product comprising unconverted hydrocarbons, acetylene, ethylene, CO, H2; contacting a first portion of CO2 free product with aprotic polar solvent to produce acetylene solution and first gas stream comprising unconverted hydrocarbons, ethylene, CO, H2; contacting acetylene solution with a second portion of CO2 free product to produce hydrogenation product comprising aprotic polar solvent, unconverted hydrocarbons, ethylene, CO, H2; separating hydrogenation product into aprotic polar solvent stream and second gas stream comprising unconverted hydrocarbons, ethylene, CO, H2; separating second gas stream into ethylene stream and third gas stream comprising unconverted hydrocarbons, CO, H2; and introducing first and/or third gas streams to a reactor to produce methanol.

1 . A method for producing ethylene and methanol comprising:
 (a) introducing a first fuel gas stream and an oxidant gas to a combustion zone to produce a combustion product;   (b) introducing a first reactant mixture to a first reaction zone, wherein the first reactant mixture comprises a hydrocarbon stream and at least a portion of the combustion product, wherein the hydrocarbon stream comprises natural gas and/or higher hydrocarbons, and wherein the combustion product heats the hydrocarbon stream to a temperature effective for a pyrolysis reaction;   (c) allowing at least a portion of the first reactant mixture to react via the pyrolysis reaction and produce a pyrolysis reaction product, wherein the pyrolysis reaction product comprises unconverted hydrocarbons, acetylene, ethylene, carbon monoxide (CO), hydrogen (H 2 ), water (H 2 O), and carbon dioxide (CO 2 );   (d) introducing at least a portion of the pyrolysis reaction product to a carbon dioxide removal unit to produce a CO 2  stream and a CO 2  free product stream, wherein the CO 2  stream comprises CO 2  and H 2 O, and wherein the CO 2  free product stream comprises unconverted hydrocarbons, acetylene, ethylene, CO, and H 2 ;   (e) contacting a first portion of the CO 2  free product stream with an aprotic polar solvent in an acetylene absorption unit to produce an acetylene solution and a first gas stream, wherein the aprotic polar solvent absorbs at least a portion of the acetylene of the first portion of the CO 2  free product stream to produce the acetylene solution, wherein the acetylene solution comprises at least a portion of the acetylene of the first portion of the CO 2  free product stream, and wherein the first gas stream comprises unconverted hydrocarbons, ethylene, CO, and H 2 ;   (f) contacting at least a portion of the acetylene solution with a second portion of the CO 2  free product stream in a liquid phase hydrogenation reactor to produce a hydrogenation product, wherein the CO 2  free product stream hydrogenates at least a portion of the acetylene of the acetylene solution to produce ethylene, wherein the hydrogenation product comprises aprotic polar solvent, unconverted hydrocarbons, ethylene, CO, and H 2 ;   (g) separating at least a portion of the hydrogenation product into an aprotic polar solvent stream and a second gas stream, wherein the aprotic polar solvent stream comprises at least a portion of the aprotic polar solvent of the hydrogenation product, and wherein the second gas stream comprises unconverted hydrocarbons, ethylene, CO, and H 2 ;   (h) separating at least a portion of the second gas stream into an ethylene stream and a third gas stream, wherein the third gas stream comprises unconverted hydrocarbons, CO, and H 2 ; and   (i) introducing at least a portion of the first gas stream and/or at least a portion of the third gas stream to a second reaction zone to produce methanol and a second fuel gas stream.   
     
     
         2 . The method of  claim 1  further comprising compressing at least a portion of the pyrolysis reaction product to a first pressure range of about 150 psig to about 300 psig prior to the step (d) of introducing the pyrolysis reaction product to a carbon dioxide removal unit. 
     
     
         3 . The method of  claim 2  further comprising compressing at least a portion of the second portion of the CO 2  free product stream to a second pressure range of about 200 psig to about 350 psig prior to the step (f) of contacting the acetylene solution with a second portion of the CO 2  free product stream. 
     
     
         4 . The method of  claim 1 , wherein at least a portion of the aprotic polar solvent stream is recycled to the acetylene absorption unit. 
     
     
         5 . The method of  claim 1 , wherein the aprotic polar solvent stream comprises N-methyl-2-pyrrolidone, dimethylformamide, acetone, or combinations thereof. 
     
     
         6 . The method of  claim 1 , wherein a portion of the first gas stream, a portion of the third gas stream, at least a portion of the second fuel gas stream, or combinations thereof is (i) recycled to the combustion zone as the first fuel gas stream; and/or (ii) used as a fuel stream other than the first fuel gas stream. 
     
     
         7 . The method of  claim 1 , wherein the first reactant mixture is characterized by a temperature of equal to or greater than about 700° C. 
     
     
         8 . The method of  claim 1 , wherein the first reaction zone is characterized by a residence time of from about 0.1 milliseconds (ms) to about 100 ms. 
     
     
         9 . The method of  claim 1 , wherein the first gas stream is characterized by a H 2 /CO molar ratio of from about 1.5:1 to about 3.0:1. 
     
     
         10 . The method of  claim 1 , wherein the second gas stream is characterized by a H 2 /CO molar ratio of from about 0.5:1 to about 1.5:1. 
     
     
         11 . The method of  claim 1  further comprising (i) compressing at least a portion of the first gas stream and/or at least a portion of the third gas stream to a third pressure range of about 1,000 psig to about 1,300 psig to produce a compressed gas stream; and (ii) introducing at least a portion of the compressed gas stream to the second reaction zone. 
     
     
         12 . The method of  claim 11 , wherein the second reaction zone has an M ratio requirement of from about 2.0 to about 2.2; wherein the compressed gas stream is characterized by an M ratio of from about 2.0 to about 2.2; and wherein the M ratio is a molar ratio defined as (H 2 —CO 2 )/(CO+CO 2 ). 
     
     
         13 . The method of  claim 11 , wherein the compressed gas stream is characterized by an M ratio other than from about 2.0 to about 2.2, wherein the M ratio is a molar ratio defined as (H 2 —CO 2 )/(CO+CO 2 ), and wherein at least a portion of the compressed gas stream is subjected to a water-gas shift reaction to produce a shifted gas stream characterized by an M ratio of from about 2.0 to about 2.2. 
     
     
         14 . The method of  claim 13 , wherein at least a portion of the shifted gas stream is introduced to the second reaction zone. 
     
     
         15 . The method of  claim 1 , wherein the hydrocarbon stream comprises methane, natural gas, natural gas liquids, associated gas, well head gas, enriched gas, higher hydrocarbons, paraffins, olefins, alcohols, oxygenates, C 1  to C 6  compounds, or combinations thereof. 
     
     
         16 . The method of  claim 1 , wherein the second reaction zone comprises a catalyst comprising Cu, Cu/ZnO, Cu/ThO 2 , Cu/Zn/Al 2 O 3 , Cu/ZnO/Al 2 O 3 , Cu/Zr, or combinations thereof. 
     
     
         17 . The method of  claim 1 , wherein the first gas stream comprises H 2  in an amount of from about 40 mol % to about 60 mol %. 
     
     
         18 . A method for producing ethylene and hydrogen comprising:
 (a) introducing a first fuel gas stream and an oxidant gas to a combustion zone to produce a combustion product;   (b) introducing a first reactant mixture to a first reaction zone, wherein the first reactant mixture comprises a hydrocarbon stream and at least a portion of the combustion product, wherein the hydrocarbon stream comprises natural gas and/or higher hydrocarbons, and wherein the combustion product heats the hydrocarbon stream to a temperature effective for a pyrolysis reaction;   (c) allowing at least a portion of the first reactant mixture to react via the pyrolysis reaction and produce a pyrolysis reaction product, wherein the pyrolysis reaction product comprises unconverted hydrocarbons, acetylene, ethylene, carbon monoxide (CO), hydrogen (H 2 ), water (H 2 O), and carbon dioxide (CO 2 );   (d) introducing at least a portion of the pyrolysis reaction product to a carbon dioxide removal unit to produce a CO 2  stream and a CO 2  free product stream, wherein the CO 2  stream comprises CO 2  and H 2 O, and wherein the CO 2  free product stream comprises unconverted hydrocarbons, acetylene, ethylene, CO, and H 2 ;   (e) contacting a first portion of the CO 2  free product stream with an aprotic polar solvent in an acetylene absorption unit to produce an acetylene solution and a first gas stream, wherein the aprotic polar solvent absorbs at least a portion of the acetylene of the first portion of the CO 2  free product stream to produce the acetylene solution, wherein the acetylene solution comprises at least a portion of the acetylene of the first portion of the CO 2  free product stream, and wherein the first gas stream comprises unconverted hydrocarbons, ethylene, CO, and H 2 ;   (f) contacting at least a portion of the acetylene solution with a second portion of the CO 2  free product stream in a liquid phase hydrogenation reactor to produce a hydrogenation product, wherein the CO 2  free product stream hydrogenates at least a portion of the acetylene of the acetylene solution to produce ethylene, wherein the hydrogenation product comprises aprotic polar solvent, unconverted hydrocarbons, ethylene, CO, and H 2 ;   (g) separating at least a portion of the hydrogenation product into an aprotic polar solvent stream and a second gas stream, wherein the aprotic polar solvent stream comprises at least a portion of the aprotic polar solvent of the hydrogenation product, and wherein the second gas stream comprises unconverted hydrocarbons, ethylene, CO, and H 2 ;   (h) separating at least a portion of the second gas stream into an ethylene stream and a third gas stream, wherein the third gas stream comprises unconverted hydrocarbons, CO, and H 2 ; and   (i) introducing at least a portion of the first gas stream and/or at least a portion of the third gas stream to a pressure swing adsorption (PSA) unit to produce a hydrogen stream and a PSA fuel gas product stream.   
     
     
         19 . The method of  claim 18 , wherein the third gas stream comprises H 2  in an amount of from about 25 mol % to about 40 mol %. 
     
     
         20 . A method for producing ethylene, methanol and hydrogen, the method comprising:
 (a) introducing a first fuel gas stream and an oxidant gas to a combustion zone to produce a combustion product;   (b) introducing a first reactant mixture to a first reaction zone, wherein the first reactant mixture comprises a hydrocarbon stream and at least a portion of the combustion product, wherein the hydrocarbon stream comprises natural gas and/or higher hydrocarbons, and wherein the combustion product heats the hydrocarbon stream to a temperature effective for a pyrolysis reaction;   (c) allowing at least a portion of the first reactant mixture to react via the pyrolysis reaction and produce a pyrolysis reaction product, wherein the pyrolysis reaction product comprises unconverted hydrocarbons, acetylene, ethylene, carbon monoxide (CO), hydrogen (H 2 ), water (H 2 O), and carbon dioxide (CO 2 );   (d) introducing at least a portion of the pyrolysis reaction product to a carbon dioxide removal unit to produce a CO 2  stream and a CO 2  free product stream, wherein the CO 2  stream comprises CO 2  and H 2 O, and wherein the CO 2  free product stream comprises unconverted hydrocarbons, acetylene, ethylene, CO, and H 2 ;   (e) contacting a first portion of the CO 2  free product stream with an aprotic polar solvent in an acetylene absorption unit to produce an acetylene solution and a first gas stream, wherein the aprotic polar solvent absorbs at least a portion of the acetylene of the first portion of the CO 2  free product stream to produce the acetylene solution, wherein the acetylene solution comprises at least a portion of the acetylene of the first portion of the CO 2  free product stream, and wherein the first gas stream comprises unconverted hydrocarbons, ethylene, CO, and H 2 ;   (f) contacting at least a portion of the acetylene solution with a second portion of the CO 2  free product stream in a liquid phase hydrogenation reactor to produce a hydrogenation product, wherein the CO 2  free product stream hydrogenates at least a portion of the acetylene of the acetylene solution to produce ethylene, wherein the hydrogenation product comprises aprotic polar solvent, unconverted hydrocarbons, ethylene, CO, and H 2 ;   (g) separating at least a portion of the hydrogenation product into an aprotic polar solvent stream and a second gas stream, wherein the aprotic polar solvent stream comprises at least a portion of the aprotic polar solvent of the hydrogenation product, and wherein the second gas stream comprises unconverted hydrocarbons, ethylene, CO, and H 2 ;   (h) separating at least a portion of the second gas stream into an ethylene stream and a third gas stream, wherein the third gas stream comprises unconverted hydrocarbons, CO, and H 2 ;   (i) introducing a first portion of the combined first gas stream and third gas stream to a second reaction zone to produce methanol and a second fuel gas stream; and   (j) introducing a second portion of the combined first gas stream and third gas stream to a pressure swing adsorption (PSA) unit to produce a hydrogen stream and a PSA fuel gas product stream.